Fluid operated escapement device



May 24, 1960 B. DARSIE FLUID OPERATED EISCAPEMENT DEVICE Filed April 3,1958 v-JLe.

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United States PatentO FLUID OPERATED ESCAPEMENT DEVICE BurnsDarsie,Rockford, Ill., assignor to Dixon Automane Tool, Inc., Rockford, 111., acorporation of Illinois Filed Apr. 3, 1958, Ser. No. 726,264 6 Claims.(Cl. 221-298) The present invention relates generally to articlecontrolling escapement mechanisms and more particularly to an escapementmechanism for delivering small articles one by one from a storagemagazine.

It is the primary aim of the invention to provide a novel fluid operatedescapement release mechanism that is positive acting and reliable whilebeing exceptionally economical to manufacture.

With more particularity it is an object to provide a fluid pressureoperated escapement mechanism that does not rely upon a valvearrangement for proper sequential operation and therefore avoidscritical machining and adjusting problems. In greater detail, it is anobject to provide an escapement mechanism as characterized above,comprising a pair of units inwhich the retaining and releasingoperations occur in an accurately timed and consistent sequence so as toinsure the feeding of articles one by one. In one of the aspects of theinvention means are provided for causing the units to act diiferentiallyto insure timing overlap, and thus positive gating, even though theunits are supplied with fluid simultaneously and from the same fluidsource. It is nevertheless an object to provide an article release unitand a stack retaining unit, with each of the units having a large numberof common parts so as to minimize manufacturing costs.

It is also an object to provide an escapement mechanism of the abovetype that is readily adaptable to a wide variety of operating situationsin that its component units can be individually positioned and mountedso as to control articles of widely varying sizes. It is a relatedobject to provide an escapement mechanism having the abovecharacteristics which is also extremely simple to adjust for handlingarticles of various sizes and shapes since its two component units aremerely coupled to a common air pressure source and no critical timingadjustment is needed.

Other objects and advantages of the invention will be-v come apparentupon reading the attached detailed description and upon reference to thedrawings in which:

Figure 1 is an elevation view of an escapement mechanism embodying thepresent invention; V

Fig. 2 is a stop motion fragmentary'view similar to Figure 1 showing theescapement mechanism in an intermediate position of its operating cycle;

Fig. 3 is a fragmentary stop motion view similar to Fig. 2 showing theparts of the escapement mechanism in their operative positions;

Fig. 4 is a section taken along line 4-4 of Fig. 1;

Fig. 5 is a section taken along the line 5-5 of Fig. 1; and a Fig. 6 isan elevation view similar to Fig. 1 showing a modified installation ofthe escapement mechanism embodying the present invention.

While the invention will be described in connection with a preferredembodiment, it will be understood that I do not intend to limit theinvention to that em bodiment. I On the contrary, I intend to cover allalternatives, modifications and equivalents as may be ineluded withinthe spirit and scope of the invention as defined by the appended claims;

Turning now to Figure 1, there is shown an escapement mechanism 10,embodying the present invention, arranged to deliver, one by one, aseries of articles A. In the illustrated embodiment, the articles A arealined in a magazine 11 which defines a downwardly inclined pathway12.The articles A are prevented from sliding down the pathway 12 by theirengagement with an article release plunger 15 that extends into thepathway 12.

Single articles are released from the magazine 11' by moving the articlerelease plunger 15 from the pathway 12 after a stack retaining plunger16 has been urged into the pathway to arrest movementof the stack ofarticles behind the first or lowermost article in the stack. The

sequential operation of the plungers 15, 16 is illustrated I Figs. 1, 2and 3. In Fig. l'theplungers are shown in their normal rest positionswith the articles A held in the magazine 11 by the plunger 15. In Fig.2, the stack retaining plunger 16 has been urged downwardly intoengagement with the second article of the stack while the plunger-15remains extended into the pathway 12. In

Fig. 3, the stack releasing plunger 15 has been withdrawn from thepathway 12 so as to release the lowermost articleA while the stackretaining plunger 16-remains effective to hold the remaining articles inposition. The plunger operating sequence is, of course, reversed whenthe plungers are returned to their normal rest positions. That is, theplunger 15 is lowered until itagain extends into the pathway 12 beforethe plunger 16 is raised from the pathway to its normal position.

In accordance with the present invention, the plungers 15, 16 areresiliently urged into their normal rest positions and are operated by apair of fluid pressure motors coupled to a common source of fluidpressure; the eflece tive, piston areas of the motors and the resilientforces on the plungers being so related as to urgegtheplunger ,16 intothe pathway 12'before the plunger 15 is moved from the pathway upon theintroduction of fluid pressure. In

this way, the articles A may be released from the magazine 11 one by onein the manner described above.

In the preferred embodiment, the plungers 15, 16 have formed integrallytherewith pistons 17 and 18, respectively. The piston 17. is slidablyfitted in a cylinder 19 normal rest positions, a spring 25 is compressedinthe cylinder 19 and arranged to bear againstth e piston 17,

and a spring 26 is compressed in the cylinder 20 and arranged to bearagainst the piston 18. The spring 25 is seated about a pin 27 formedintegrally at the top of the piston 17, and the spring 26 is seated bybeing fitted about a collar 30 formed on the piston 16.

In order to supply fluid pressure and operate the plungers 15, 16, aconnector 31 is provided for introducing fluid under pressure into thecylinder 19 on the side of the piston 17 opposite the spring 25, and aconnector 32 is provided for introducing fluid into the cylinder20 onthe side of the piston 18 opposite the spring 26. The connectors 31, 32are coupled to a common source of fluid pressure by a conduit assembly33, and avalve 34 is provided in the assembly for controlling the flowof fluid pressure to the cylinders 19, 20.

Preferably, proper sequential operation of the plungers 15, 16 isassured by two distinct factors. First, it will be seen that theeffective piston area against which the fluid pressure may act in movingthe plunger is significantly less than the eflective piston area againstwhich the fluid pressure acts in moving the plunger 16.. In cylinder 20,the fluid pressure acts against a piston area substantially equal to thecross-sectional area of the cylinder. In cylinder 19,because of theinterconnection of the plunger 15 with the piston 17, the eflectivepiston area is substantially reduced. It will therefore be seen that,other factors being equal, as fluid pressure is uniformly developed ineach of the cylinders 19 and 20, the higher force on piston 18 will movethe plunger 16 toward the pathway 12 before the plunger 15 is operated.

The second factor for securing sequential operation of the two plungers15, 16 is the fact that spring 25 is selected so as to exert a strongerforce holding the plunger 15 in its normal position than is exerted bythe spring 26 holding the plunger 16 in its normal position. It will beunderstood therefore, that as the fluid pressure tending to move theseplungers is gradually. increased, the plunger 16 will be moved beforethe plunger 15 because of the lighter spring force which must beovercome.

In summary then, operation of the valve 34 will admit fluid underpressure into each of the cylinders 19, through the respectiveconnectors 31, 32. The greater effective piston area of piston 18, andthe lighter spring 26, will cause operation of the plunger 16 to itsFig. 2 position before the plunger 15 is moved. Thus, sequentialoperation is obtained without valving fluid pressure first to one andthen the other of the cylinders.

It is a feature of the invention that the plungers 15, 16 and theirrelated operating structure are substantial duplicates of one another.It will be noted, for example, that the plunger-piston assembly 15, 17is identical to the plunger-piston assembly 16, 18. The piston 18 isprovided with a pin 28 on its upper surface corresponding to the pin 27on the piston 17. Preferably, the pin 28 abuts the cap 24 andestablishes the normal rest position of the plunger 16. It will also beobserved that the plunger 15 is formed with a collar 29 whichcorresponds to the collar 30 on the plunger 16. In the illustratedembodiment, the collar 29 abuts the bottom wall of the cylinder 19 andthus establishes the normal rest position of the plunger 15.

Each of the pistons 17, 18 is formed with a central peripheral groove inwhich O-rings 37, 38, respectively, are fitted for establishing a fluidpressure seal between the respective pistons and their surroundingcylinders.

Not only are the plunger assemblies identical, but it will be noted thatthe cylinder blocks 21, 22 are also substantially identical. The fluidpressure connector 31 communicates with the cylinder 19 through apassage 39, and a corresponding passage 40 is provided in the block 22to serve as a discharge port for relieving back air pressure on thebottom of the piston 18. Similarly, the fluid pressure connector 32communicates with the cylinder 20 through a port 42 corresponding to aport 41 formed in the cylinder block 21 which serves to relieve the airpressure behind the piston 17 when it is operated.

By making the various component parts of the mechanism 10interchangeable, it will be appreciated that substantial savings inmanufacturing and servicing costs are effected.

For the purpose of mounting the cylinder blocks 21, 22 and the plungers15, 16 carried thereby, the blocks are provided with identically locatedsets of tapped holes 43, 44 and 44a, respectively. In the embodimentillustrated in Figs. 1 to 5, the blocks are mounted on L'-shapedbrackets 45 which are secured to the sides of the magazine 11 andfastened to the respective cylinder blocks 21, 22 by screws 46 threadedinto the tapped holes 44a.

It is a further feature of the invention that the cylinder blocks 21, 22are completely independent and-distinct with the only connection betweenthe fluid motors operating the article release piston 15 and the stackretaining piston 16 being the conduit assembly 33 which supplies fluidpressure from a common source to each of the units. The escapementmechanism 10 is, therefore, very flexible and can be readily adapted tohandle a wide variety of situations. For example, in Fig. 6, the blocks21, 22 are shown mounted on a strip 50 at right angles to one another sothat the article engaging ends of the plungers 15 and 16 are broughtinto very close proximity to one another. In this embodiment, the blocksare fastened to the strip by screws (not shown) threaded into the tappedholes 43 and 44. This enables the mechanism 10 to handle very smallarticles B.

In the preferred and illustrated arrangement for handling smallarticles, the close proximity of the plungers 15, 16 is greatly enhancedby providing the latter with pointed tips 15a, 16a, respectively. Theoperation of the plungers remains as described above.

I claim as my invention:

1. In a fluid operated escapement mechanism having a pathway down whicharticles are propelled, the combination comprising, a pair of mutuallyindependent cylinder blocks spaced along said pathway, the lowermost ofsaid blocks defining an article release cylinder and the other blockdefining a stack retaining cylinder, said cylinders having bores ofequal diameter, a pair of pistons each being slidably mounted in arespective one of said cylinders and each piston having a plungerextending from one end thereof, said plungers slidably fitting throughone end of their respective cylinder blocks so as to be movable into andout of said pathway, a first spring compressed in said article releasecylinder on the side of the associated piston opposite the plunger so asto urge the plunger from the cylinder into said pathway, a second springcompressed in said stack retaining cylinder and surrounding theassociated plunger so as to bear against the piston and urge the plungerinto the cylinder and out of said pathway, and means for introducingfluid under pressure from a common source to said cylinders on the sidesof the respective pistons opposite their respective springs whereby uponthe introduction of fluid through said means, the greater effectivepiston area in the stack retaining cylinder resulting from thepiston-cylinder connection in the article release cylinder andcorrelation of the strength of the springs automatically causes theplunger in the former cylinder to operate before operation of theplunger in the latter cylinder.

2. In a fluid operated escapement mechanism having a pathway down whicharticles are propelled, the combination comprising, a pair of mutuallyindependent cylinder blocksspaced along said pathway, the lowermost ofsaid blocks defining an article release cylinder and the other blockdefining a stack retaining cylinder, said cylinders having bores ofequal diameter, a pair of pistons each being slidably mounted in arespective one of said cylinders and each piston having a plungerextending from one end thereof, said plungers slidably fitting throughone end of their respective cylinder blocks so as to be movable into andout of said pathway, a first spring compressed in said article releasecylinder on the side of the associated piston opposite the plunger so asto urge the plunger from the cylinder into said pathway, a second springcompressed in said stack retaining cylinder and surrounding theassociated plunger so as to bear against the piston and urge the plungerinto the cylinder and out of said pathway, said first spring beingeffective to exert a stronger force on its piston than the force exertedby said second spring on its piston, and means for introducing fluidunder pressure from a common source to said cylinders on the sides ofthe respective pistons opposite their respective springs whereby uponthe introduction of fluid through said means, the greater effectivepiston area in the stack retaining cylinder resultmg from thepiston-cylinder connection in the article automatically causes theplunger in the former cylinder to operate before operation of theplunger in the latter cylinder.

3. In a fluid pressure operated escapement mechanism having a pathwayfor the movement of articles, the combination comprising, an articlerelease cylinder and a stack retaining cylinder positioned along saidpathway, a pair of pistons having plungers coupled thereto and beingslidably mounted in respective ones of said cylinders so as to move saidplungers into and out of said pathway, a pair of springs associatedrespectively with each of said cylinders with the article releasecylinder spring urging the associated plunger toward an article blockingposition in said pathway and the stack retaining cylinder spring urgingthe associated piston to an article clearing position out of saidpathway, and means for introducing fluid under pressure from a commonsource to each of said cylinders so that the fluid pressure acts inopposition to the force of said springs, the eflective piston area inthe article release cylinder being less than the elfective piston areain the stack retaining cylinder and said article release cylinder springbeing stronger than said stack retaining cylinder spring so that uponintroduction of fluid pressure the stack retaining cylinder plunger isurged into said pathway before the article release cylinder plunger ismoved from said pathway.

4. In a fluid pressure operated escapement mechanism having a pathwayfor the movement of articles, the combination comprising, an articlerelease cylinder and a stack retaining cylinder positioned along saidpathway, a pair of pistons having plungers coupled thereto and beingslidably mounted in respective ones of said cylinders so as to move saidplungers into and out of said pathway, a pair of springs associatedrespectively with each of said cylinders with the article releasecylinder spring urging the associated plunger toward an article blockingposition in said pathway and the stack retaining cylinder spring urgingthe associated piston to an article clearing position out of saidpathway, and means for introducing fluid under pressure from a commonsource to each of said cylinders so that the fluid pressure acts inopposition to the force of said springs, said article release cylinderspring being stronger than said stack retaining cylinder spring so thatupon introduction of fluid pressure the stack retaining cylinder plungeris urged into said pathway before the article release cylinder plungeris moved from said pathway.

5. In a fluid pressure operated escapement mechanism having a pathwayfor the movement of articles, the combination comprising, an articlerelease cylinder and a stack retaining cylinder positioned along saidpathway, a pair of pistons having plungers coupled thereto and beingslidably mounted in respective ones of said cylinders so as to move saidplungers into and out of said pathway,

a pair of springs associated respectively with each of said cylinderswith the article release cylinder spring urging the associated plungertoward an article blocking position in said pathway and the stackretaining cylinder spring urging the associated piston to an articleclearing position out of said pathway, and means for introducing fluidunder pressure from a common source to each of said cylinders so thatthe fluid pressure acts in opposition to the force of said springs, theeffective piston area in the article release cylinder being less thanthe effective piston area in the stack retaining cylinder and thestrength of the springs being correlated so that upon introduction offluid pressure the stack retaining cylinder plunger is urged into saidpathway before the article release cylinder plunger is moved from saidpathway.

6. In a fluid pressure operated escapement mechanism having a pathwayfor the movement of articles, the combination of, an article releasecylinder and a stack retaining cylinder positioned along said pathway, apair of pistons having plungers coupled thereto and being slidablymounted in respective ones of said cylinders so as to move said plungersinto and out of said pathway,

a pair of springs associated respectively with each of said cylinderswith the article release cylinder spring urging the associated plungertoward an article blocking position in said pathway and the stackretaining cylinder spring urging the associated piston to an articleclearing position out of said pathway, and means for introducing fluidunder pressure from a common source to each of said cylinders so thatthe fluid pressure acts in opposition to the force of said springs, theeffective piston area of each piston and the strength of the springsacting against each piston being correlated so that upon introduction offluid pressure the stack retaining cylinder plunger is I urged into saidpathway before the article release cylinder plunger is moved from saidpathway.

References Cited in the file of this patent UNITED STATES PATENTS2,611,911 Graham et al. Sept. 30, 1952

